Method and apparatus for making envelopes



J. W. LENK March 22, 1966 METHOD AND APPARATUS FOR MAKING ENVELOPES 4 Sheets-Sheet 1 INVENTOR. James W Len/r Filed Oct. 19, 1962 W WL ATTORNEY March 22, 1966 J, w, LENK 3,241,465

METHOD AND APPARATUS FOR MAKING ENVELOPES Filed Oct. 19, 1962 4 Sheets-Sheet 2 ATTORNEY March 22, 1966 J. W. LENK METHOD AND AI-PARATUS FOR MAKING ENVELOPES 4 Sheets-Sheet 5 Filed Oct. 19. 1962 YMM IN VEN TOR. James W. e/rk ATTORNEY March 22, 1966 w LENK 3,241,465

7 METHOD AND APPARATUS FOR MAKING ENVELOPES Filed Oct. 19, 1962 4 Sheets-Sheet 4 A TTOR/VE Y United States Patent 3,241,465 METHOD AND APPARATUS FOR MAKING ENVELOPES James W. Lenk, Shawnee Mission, Kans., assignor to Berkley Machine Company, Kansas City, Mo., 21 corporation of Missouri Filed Oct. 19, 1962, Ser. No. 231,634 Claims. (Cl. 93-62) This invention relates to a method and apparatus for making envelopes at higher speeds than possible with conventional rotary envelope making machines.

For example, in the modern rotary envelope making machine, the envelope blanks are fed thereinto in lapped squamiform relation, so that only the portions of the sealing flaps are exposed for application of the seallng gum as a continuous band of adhesive, after which the blanks are slightly moved apart to break the band of adhesive and the blanks, still in lapped formation, are passed through a drier. On leaving the drier, the blanks are completely separated and passed one at a time through scoring, side flap folding, side flap gumming, and bottom flap and closure flap folding mechanisms. It is, therefore, obvious that the blanks must progress at a considerably higher rate of linear speed through the latter sections of the machine than through the first section, in

order to maintain a continuous output of finished envelopes in accordance with the feed of the blanks into the machine. The first section of the machine, that is, where the blanks are moved in squamiform relation, can be successfully operated at much higher speeds, but the speed of the blanks through the latter sections of the machine must be limited to a speed at which the gum will not sling off the side gum applicators under centrifugal action. If an attempt is made to operate the machine at higher speeds, the gum will sling off the surface of the side gum applicators onto the machine and the envelopes being made therein, consequently an inferior product results, and the machine must be shut down at frequent intervals for wash-up and elimination of ball-ups.

There have been many efforts to reduce the cost of making envelopes, but low cost cannot be attained merely by increasing the speed of present rotary envelope making machines.

It is, therefore, a principal object of the present invention to provide an improved method and apparatus for applying the side flap sealing gum, in order to attain higher speeds and output capacity of envelope making machines Without splattering of the gum.

In carrying out the invention, I have provided means for applying the gum to the side flaps of the envelope blanks while the blanks are being conveyed in squamiform relation at the slower speed for applying the closure flap gum. In this way, the side flap sealing gum is also applied as continuous bands of gum on the face of the blanks opposite to the one to which the closure flap gum is applied, after which the side flap gum is dried simultaneously with the closure flap gum.

As a result, the first section of the machine can be operated at higher speed up to the point Where slinging of the gum by the applicator rollers might become objectionable. The following sections of the machine can be operated at correspondingly higher speed necessary to draw out and separate the blanks, since there is no gum to be applied while the blanks are moving at such increased speed. It is, however, necessary to condition the dried gum on the side flaps, and this may be accomplished by moistening the gum with water or the like prior to folding of the bottom flaps thereover. The speed of the moistening apparatus is not critical, because if the moistener should happen to sling some water, the

water will not damage the envelopes or the machine in which they are manufactured.

In accomplishing the above and other objects of the invention, as hereinafter described, I have provided an improved method and machine, the preferred form of which is illustrated in the accompanying drawings, wherein:

FIG. 1 is a schematic view showing the envelope blanks as they are carried in squamiform relation through the closure flap and side flap gumming stages.

FIG. 1A is a continuation of the schematic view illustrated in FIG. 1, and showing the envelope blanks as they proceed through the scoring, side flap folding, side flap gum moistening, and bottom and closure flap folding stages.

FIG. 2 is a view of one of the blanks as seen from the opposite face from that shown in FIG. 1, showing the sealing gum on the side flaps.

FIG. 3 is a longitudinal section of the first or front section of an envelope making machine for making envelopes in accordance with the steps disclosed in FIG. 1.

FIG. 3A is a longitudinal section of the other end of the envelope making machine equipped with the mechanisms for performing the steps illustrated in FIG. 1A, this being directly aligned with the right end of the front section shown in FIG. 3.

FIG. 4 is a fragmentary section taken on the line 44 of FIG. 3, particularly illustrating the applicator for applying gum to the closure flaps.

FIG. 5 is a similar section on the line 5-5 of FIG. 3, showing the gum applicators for applying gum to the side flaps.

FIG. 6 is a section on the line 6-6 of FIG. 3A, showing the apparatus for applying moisture to the dried gum on the side flaps.

Referring more in detail to the drawings:

1 designates one type of envelope blank from which envelopes are formed in accordance with the present invention. Each blank 1 includes a central portion 2 (FIGS. 1 and 2) of generally rectangular shape, and projecting from two opposite sides thereof are side flap portions 3 and 4 and from the other two sides a bottom flap 5 and a closure flap 6.

The blanks thus shaped are folded and gummed by a novel method in a rotary envelope making machine, designated generally as 7, that functions successfully at speeds substantially greater than the speeds of present day Inachines, such as a modification of the envelope making machine illustrated and described in Patent No. 2,132,227, issued to Winkler and Dunnebier, October 4, 1938.

The envelope making machine as modified also is of novel construction to make envelopes in accordance with the present invention, and includes a first or front section 8, a gum drying section 9 that extends rearwardly along the lower portion of the front section of the machine and under a back section 10, including a scoring section 11, side flap folding section 12, a bottom and closure flap folding section 13, and a delivery table 14.

The first section 8 of the machine has a support 15 for carrying a stack of the blanks 1. i The section 8 also ini eludes means 16 as described in said patent for drawing the blanks in consecutive order from the bottom of the stack and passing them by means of a series of rollers 17, to a staggering mechanism 18 of conventional design and illustrated in said patent, whereby the blanks are overlapped in squarniform relation as shown at 19 in, FIG. 1. In this relation the blanks are lapped so that. only portions 20 of the closure flaps 6 are exposed for application of a continuous band of gum 21 thereto as the blanks are carried downwardly in contact with a roller applicator 22 which receives gum from a gum box 23 through a pickup roller 24 and a transfer roller 25. In the squamiform lapping of the blanks 1, the forward marginal edges 26 of the side flaps 3 and 4 are also exposed on the underside faces of the blanks, and the present invention utilizes this feature to carry out application of sealing gum thereto also by continuous bands, as now to be described.

Preferably, following the application of the gum by the roller applicator 22, the lapped blanks are brought into contact with laterally spaced rollers 27 and 28 that are positioned at the opposite face of the blanks to apply gum in continuous bands, as indicated by the dotted lines 29 and 30 (FIG. 1), to the underfaces of the side flaps 3 and 4, to cover the exposed forward marginal edges 26 of the side flaps 3 and 4.

It may be that more gum need be provided upon each side flap 3 and 4, in which case the blanks, after the band of gum 21 has been applied to the closure flaps 6, may be slightly moved apart as indicated at 31 (FIG. 1). The gum 32 on the individual blanks is spaced apart. This spaces the forward edges 26 of the side flaps 3 and 4 of one blank from corresponding edges of a preceding blank a sufficient distance so that when the blanks are thus slightly moved apart the gum 33 applied thereto by the rollers 27 and 28 is of the desired width. This slight advancement of the blanks also separates the gum on the closure flaps 6 so that the blanks do not stick to each other. However, this may be accomplished when the blanks are delivered to the drier section 9.

For the application of the gum to the closure flaps 6, the blanks can be carried between belt conveyors 34 and 35 as illustrated and described in the Patent No. 2,132,227 above mentioned, but when the blanks are delivered to the applicators 27 and 28 they must be carried between more narrow belts that grip the blanks between the stripes of adhesive that are applied to the upper and lower faces of the lapped blanks. In order that the blanks may be gripped more securely in spite of the narrower grip, pairs of chains 36 and 37 are utilized of the type described in the Winkler and Dunnebier Patent No. 3,021,610, dated Feb. 20, 1962. Such chains have links 38 carrying rubber blocks 39 that firmly grip the blanks therebetween (FIGS. 1 and The applicators 27 and 28 are each supplied with adhesive from pans 40 and 41, from which the adhesive is gathered on pickup rollers 42 and 43 and is applied to the applicator rolls 27 and 28 by transfer rollers 44 and 45. The envelope blanks are backed by counter rollers 27' and 28 or the like, so that continuous bands of adhesive 29 and 30 are applied to the side flaps 3 and 4 while the blanks are retained in squamiform or overlapped relation.

The slight spacing above mentioned may be made while the blanks are transferred from between the belts 34 and 35 and the chains 36 and 37.

The blanks continue between the chain conveyors 36 and 37, as shown in FIG. 5, to the drying section 9, Where they are fed between slightly faster belts or chains 46 and 47 which register with the belts 36 and 37 and grip the same parts of the blanks therebetween. However, on emerging from the chains 36 and 37, they are slightly separated by a mechanism 48 as described in the above mentioned Patent No. 3,021,610, so that the gum on the individual blanks does not stick to the gum on the adjacent blanks while being dried in the drying section 9. The conveyor belts 46 and 47 are preferably of the same construction as the chains 36 and 37. The gum 32 of the closure flaps and the gum stripes 33 on the side flaps 3 and 4 are dried by the time the blanks reach the opposite end of the machine and are transferred, still in lapped relation, between belts 49 and 50 and around a drum 51 onto a horizontal run 52 of the section of the machine, as described in Patent 2,132,227.

As the lapped blanks enter the section 11, the blanks are drawn from lapped condition by a segment roller 53 and a roller 54 and are delivered to a faster mowing roller mechanism 55, so that the individual blanks are drawn out and completely separated from the adjacent blanks, to be separately and consecutively carried through the bottom and closure flap scoring rollers 56 and 57. The blanks advance to the side flap folding section 12. Upon folding over the side flaps 3 and 4 by folders 58, the gum stripes 33 thereon are brought into an upwardly facing position (see FIG. 6), where continued movement of the partially folded blanks carries the gum stripes 33 under moistening rollers 59 and 60, which may have pads 61 and 62 thereon that are kept moistened by moisture from transfer rollers 63 contacting a pickup roller 64 in a pan 65 which contains water or other moistening liquid. After the application of moisture to the gum stripes 33, the partially folded blank is continued to a bottom flap folding mechanism 66, one type of which is illustrated in an application for patent Serial No. 824,279, now Patent No. 3,088,382, filed by Winkler and Dunnebier, where the bottom flaps 5 are folded over the moistened gum stripes 30 on the side flaps 3 and 4 of each blank and are pressed into sealing contact therewith. Briefly, the bottom flap folding mechanism 66 includes rollers 67 and 68 for directing the blanks up a ramp 69 until suction ports in the roller 68 seize the blank back of the bottom score 70 (FIG. 1A) and start the blank under a roller 71. This starts an initial bottom fold that is carried between the rollers 68 and 71, thereby laying the bottom flap 5 over the side flaps 3 and 4 as shown in FIG. 1A. Continued movement of the folded blank causes it to pass between pressing rollers 72 and 73, to complete the seal with the side flaps.

If the closure flaps 6 are to be folded, the body of the envelope is diverted into a trap 74. At this time suction in the roller 73 seizes the flap 6 to draw the envelope down between the roller 73 and a roller 75, to crease the closure flap fold. The envelopes are then discharged into spiral feeders 76 which push the envelopes into the stack on the table 14.

It is apparent that all of the gum is applied to the blanks in the slower moving section of the machine, with the blanks lapped in squamiform relation, consequently, the speed of this section of the machine can be at least up to the point at which the gum might start to spray or sling from the applicators. A slight spray of the gum is permissible because one blank covers the other in such manner that the spray would merely fall upon the areas to which the gum is applied. Since the gum is dried prior to any scoring or folding operations, the mechanisms therefore can be operated at such a high speed as to enable the blanks to be dealt with at the maximum permissible speed at which they are conveyed in squ-amiform relation through the first section of the machine. If any spray is produced by the gum moisteners, it is in no way harmful to the product or the machine.

Various mechanisms for forming the blanks into envelopes may be employed with the gumming and moistening mechanisms of the present invention, and I do not Wish to restrict the invention to the specific mechanisms illustrated and described. Any mechanisms capable of performing the required steps, which include squamiform lapping of the blanks, applying gum as continuous bands to the closure flaps and to the side flaps, drying the applied gum, separating the blanks, folding over the side flaps, and restoning the sticky characteristics to the side flap sealing gum, may be used to provide the advantages described.

What I claim and desire to secure by Letters Patent is:

1. A method of making envelopes from blanks having bottom, side and closure flaps, comprising lapping the blanks in squamiforrn relation to oppose areas of the closure flaps to be gummed at one face of the lapped blanks and to expose simultaneously leading portions of said side flaps on the opposite face of the lapped blanks,

applying gum to both of said exposed areas at the respective faces of the blanks while the blanks remain lapped in said squamiform relation and are moving at a relatively slow speed,

slightly separating the blanks to part the moist gum on one blank from the moist gum of the adjacent blanks while the blanks are retained in squamiform relation,

drying the gums,

separating the blanks one at a time from said squamiform relation sufficiently to permit folding over the side flaps .by increasing the blank conveyor speed after the gum is dried,

folding over the side flaps,

reactivating the gum on said areas of the side flaps while the blanks move at a higher speed than their movement through the adhesive portion of the machine to enable bottom and side flaps to be secured together, and

turning the bottom flaps over the side flaps to make sealing contact with the moistened gum.

2. A method as defined in claim 1 wherein the gum is applied in continuous bands at the same time to respective opposite faces of the lapped blanks.

3. A method as defined in claim 1 wherein the blanks are advanced through the gum applier without changing the squamiform relation of the blanks with respect to each other.

4. An apparatus for making envelopes from blanks having bottom, side and closure flaps, including means for conveying the blanks in squamiform relation through a fixed path in a continuous direction at a relatively slow speed,

a gum applicator opposite each face of the conveying means for applying gum substantially simultaneously to the closure and side flaps of the blanks while advancing at relatively slow speed,

means for slightly shifting the blanks to separate the moist gum on one blank from the moist gum on the adjacent blanks,

a dryer in the path of the blanks as they are advanced by said conveying means for simultaneously drying the gum applied by said applicators,

a faster conveyor,

means for seizing and drawing out the blanks from the first conveying means and delivering them to the faster conveyor to carry the blanks in consecutive order,

said flalp folding means at opposite sides of the faster conveyor to turn over the side flaps,

FRANK E.

means for reactivating the gum to the side flaps, and means extending transversely of the faster conveyor for folding the bottom flaps into sealing contact with moistened gum on the side flaps of successive blanks. 5. A method of increasing the capacity of envelope machines to produce finished envelopes by depositing adhesive discriminately only on the sealing areas of the opposite sides of the closure and end flaps during the relatively slow travel of the blanks While being maintained in squami-form relationship comprising lapping the blanks in sqnamiforrn relation to expose the interior areas of the closure flaps to be gummed at one face of the lapped blanks and to expose simultaneously leading portions of said side flaps on the exterior opposite face of the lapped blanks, conveying the lapped blanks in one direction only at a low speed and maintaining the exterior face of the blank in the same direction in its travel through the gumming portion of the machine, applying moist gum discriminately and at maximum speed of the applicator subject to centrifugal force limitation so that adhesive is applied only to both of said exposed areas simultaneously at the respective faces of the blanks while the blanks remain lapped in said squamiform relation and moving at a slow speed, slightly separating the blanks to part the moist gum on one blank from the moist gum of the adjacent blanks while the blanks are retained in squamiform relation, drying the gums, removing the blanks one at a time from said low speed of the squamiform blanks by increasing the conveyor speed after the gum is dried, folding over the side flaps, moistening the gum on said areas of the side flaps through means of a high speed roller while the blanks move at a higher speed than their movement through the adhesive portion of the machine to enable bottom and side flaps tobe secured together, and turning the bottom flaps over the side flaps to make sealing contact with the moistened gum.

References Cited by the Examiner UNITED STATES PATENTS BAILEY, Primary Examiner. 

1. A METHOD OF MAKING ENVELOPES FROM BLANKS HAVING BOTTOM, SIDE AND CLOSURE FLAPS, COMPRISING LAPPING THE BLANKS IN SQUAMIFORM RELATION TO OPPOSE AREAS OF THE CLOSURE FLAPS TO BE GUMMED AT ONE FACE OF THE LAPPED BLANKS AND TO EXPOSE SIMULTANEOUSLY LEADING PORTIONS OF SAID FLAPS ON THE OPPOSITE FACE OF THE LAPPED BLANKS, APPLYING GUM TO BOTH OF SAID EXPOSED AREAS AT THE RESPECTIVE FACES OF THE BLANKS WHILE THE BLANKS REMAIN LAPPED IN SAID SQUAMIFORM RELATION AND ARE MOVING AT A RELATIVELY SLOW SPEED, SLIGHTLY SEPARATING THE BLANKS TO PART THE MOIST GUM ON ONE BLANK FROM THE MOIST GUM OF THE ADJACENT BLANKS WHILE THE BLANKS ARE RETAINED IN SQUAMIFORM RELATION, DRYING THE GUMS, SEPARATING THE BLANKS ONE AT A TIME FROM SAID SQUAMIFORM RELATION SUFFICIENTLY TO PERMIT FOLDING OVER THE SIDE FLAPS BY INCREASING THE BLANK CONVEYOR SPEED AFTER THE GUM IS DRIED, FOLDING OVER THE SIDE FLAPS, REACTIVATING THE GUM ON SAID AREAS OF THE SIDE FLAPS WHILE THE BLANKS MOVE AT A HIGHER SPEED THAN THEIR MOVEMENT THROUGH THE ADHESIVE PORTION OF THE MACHINE TO ENABLE BOTTOM AND SIDE FLAPS TO BE SECURED TOGETHER, AND TURNING THE BOTTOM FLAPS OVER THE SIDE FLAPS TO MAKE SEALING CONTACT WITH THE MOISTENED GUM. 